Concrete joint insert unit



Jun 1967 OINT INSERT UNIT CONCRETE May 28 1964 File INVENTOR. {me/an f. Hah/7 a w Tram/5v5.

United States Patent O 3,323,426 CNCRETE JOINT INSERT UNIT Emea-an E. Hahn, Overland Park, Kans., assignor, by mesne assignments, to Clipper Manufacturing Company, Inc., Grandview, M0., a corporation of Massachusetts Filed May 28, 1964, Ser. No. 370,988 5 Claims. (Cl. 94-18) This invention relates to joints and the sealing of joints in pavement construction and, more particularly, to a combination joint inse-rt land sealing device for concrete slabs.

A sealer is normally provided in the contraction joints of concrete pavement -to keep water and incompressible materials out of the joint. Heretofore, compositions containing tar and asphalt have been used as sealers for this purpose, lbut these materials `are not satisfactory because of their general inability to completely adhere to the vertical faces of the adjacent slabs defining the joints and because these materials are unable to resist rupture which arises due to frequent atmospheric temperature changes causing expansion and contraction of the slabs.

To overcome the problems which arise due to the use of the aforesaid materials, the pavement construction industry has turned to the use of synthetic materials which are resilient and which not only have good sealing characteristics, but also are resistant to abrasion and oxidation and which are not adversely affected when the same are contacted by oil, gasoline, or other similar materials that may be found or spilled on roadways or the like. While some of these new synthetic materials are better than others for use in concrete pavement joints, sufce it to say that, for the most part, these materials surpass the old ltar and asphalt compositions in performance. For this reason, many states now require the use of such synthetic materials in .their roadway construction specifications not only because of the foregoing advantages over tar and asphalt, but because lof the relatively long, useful operating life of the 4materials so .that frequent replacemen-t of the sealers for-med from the synthetic materials is unnecessary.

Different techniques may be utilized for forming the Sealers of synthetic material prior to their use in `a pavement joint. As a result, these sealers can be p-recut and stored ready for use as, .and in the number desired and necessary. In this respect, different States have different requirements for joint spacing along a length of pavement. Also, State requirements specify that the sealer extend to a predetermined depth below the surface of the pavement, and also be of transverse width or thickness Ibetween a pair of upper and lower limits. Other specications require that the minimum thickness of the sealer, when compressed t-o a maximum degree, be between 1A inch and 3/8 inch, while the depth to which the entire joint insert unit extends into a mass of concrete, be approximately 1A the thickness of the pavement itself. All States do not have the same specifications of the type described and, therefore, it becomes necessary for a manufacturer Iof such joint insert units to provide different types and sizes of the units in order to meet the specifications of the various States.

The present invention is directed to a sealer which is constructed of a synthetic material of the Vabove-men- ICC tioned character and which can be made to meet various construction specifications with no substantial modification to Vthe sealer itself.

A further advantage of the joint insert unit of the instant invention lies in the fact that the same may be inserted into a mass :of soft concrete by a vibrating machine or by hand, and upon setting of the concrete, the unit is in the proper operative .position and it will have formed a plane of weakness in the desired location in the concrete to thereby prevent random cracking at various points in the corresponding concrete slab. As a result, the usual step of tirst forming a kerf in the green concrete of a pavement slab is obviated -and the sealing of the joints of a concrete pavement will be facilitated inasmuch as the placement of the joint insert unit performs the dual function of positioning the sealer for operation and forms the plane of weakness at a predetermined location in the pavement slab.

A problem which 'has arisen due to the use of synthetic materials for sealing concrete pavement joints is the effective bonding of the sealer body to the vertical faces of the -slabs which dene the joint. Ideally, in order to perform its intended function, the sealer must remain in contact with the vertical faces of the joint as the slabs move toward and away from each other upon expansion and contraction. Although different adhesives may be utilized for accomplishing this lbonding action, there has heretofore been no way in which the adhesives could be combined with a sealer so that the latter could be effectively stored for ycertain periods of time before use thereof. As a result, the adhesive must be applied to the joint simultaneously with the insertion of the sealer thereinto in order for the bonding of the sealer to the faces of the joint to occur.

The instant invention circumvents this difficulty by providing a sealer body capable of receiving a quantity of an adhesive for bonding the sealer body to the vertical faces of the pavement joint, and further includes a cap which not only maintains the body under compression for proper insertion into the joint, but .retains the adhesive in the sealer body for long periods of time without its becoming bonded to the body by the adhesive. Thus, the joint insert unit of the present invention can be constructed of predetermined sizes and shapes and supplied with the bonding adhesive so that lthe unit may be effectively stored until ready for use and the same may be readily inserted into a mass of soft conc-rete without further steps being -required -to render it completely operative. The cap is removable from the unit after the concrete lhas set so that the adhesive normally retained `by the ca-p Will lbe permitted lto contact the faces of the slabs, and following the normal setting time, bond the sealer to the vertical faces of the slab which dene the joint.

It is, therefore, .the ,primary object of the present invention to provide a joint insert unit for insertion into a mass of soft concrete to a predetermined depth to form a plane of weakness in the concrete after the latter has set, whereby the unit will effectively seal the joint formed thereby between a pair of adjacent concrete slabs. As a result the construction of concrete pavements is facilitated and rendered more efficient than has heretofore been possible.

Another object ofthis invention is the provision of a joint insert unit of the type described which may be constructed of different sizes and shapes so as to be able to conform to the various construction specifications of different states. Thus, a large number of units of specific sizes may be constructed and stored for immediate use as the need therefore arises.

A further object of the instant invention is the provision of a joint insert unit of the type described which is adapted for containing its own adhesive for bonding it to the vertical faces of the joint in which it is to be inserted whereby the step of applying the adhesive at the same time that the unit is inserted is obviated to thereby furt-her facilitate t-he construction operations with which the unit is associated.

Yet another object of the present invention is the prio-- vision of a joint insert unit which inclu-desa resilient sealer of synthetic material and a cap removably disposed thereover so that the sealer may be maintained in the cap in a compressed condition, while at the same lime, the adhesive for the sealer can be retained in a stored location by the cap, whereby, upon removal of the cap from the sealer, the adhesive will move into contact with the faces of the joint and the sealer itself will be maintained in a normally, substantially compressed state for all expanded and contracted positions of t-he faces `relative to each other.

Yet another object of the present invention is the provision of a unit of the aforesaid `character which includes a rigid base coupled with the sealer to facilitate the insertion of the latter into soft concrete to form the plane of weakness therein to thereby render unnecessary the conventional step of forming a kerf in green concrete which has heretofore been relied upon to provide the plane of weakness between a pair of adjacent concrete slabs.

Yet another object of this invention is the provision of a joint insert unit having a base of the type described which prevents the removal of the sealer from the joint as the cap is removed from the sealer whereby the sealer remains in an operative position at all times notwithstanding any force exerted thereon by the cap as` the latter is removed therefrom.

In the drawing:

FIGURE l is a cross-sectional view of the joint insert unit made pursuant to the concepts of t-he present invention and illustrating its use in a mass of concrete or the like;

FIG. 2 is a View similar to FIG. 1 but illustrating the initial contraction of the slab with the cap in place on the unit and with the unit having formed the plane of weakness;

FIG. 3 is a view illustrating a fully expanded joint, with the cap -of the joint insert unit removed so as to permit the sealer to partially expand against the vertical faces of they slabs;

FIG. 4 is an enlarged, end elevational view of the sealer in its expanded condition; and

FIG. 5 is a fragmentary, side elevational view of the cap and the sealer illustrating the manner in which the same are interconnected.

The jioint insert unit made pursuant to the concepts of the instant invention is denoted -by the numeral and includes an elongated base 12, an elongated sealer 14 secured to the base, and a cap 16 removably secured to the base 12 for removal therefrom after unit 10 has been disposed in a mass of concrete for a predetermined time.

Base 12 includes a plate-like web 18 having a length substantially equal to the length of sealer 14 and provided with a transversely triangular tip 2i) at its lower longitudinal edge. Tip 28 has a pair of normally downwardly facing surfaces 21 which converge toward each other as their lower extremities are approached to delne a lowermost leading edge 22.

A transversely U-shaped member 24 is integral with web 18 along its normally uppermost longitudinal edge,

web 18 being centrally ydisposed with respect to the bight 26 and sides 28 of member 24. A pair of longitudinally extending gripper elements 30 are integral with respective sides 28 and extend inwardly of member 24 toward the adjacent element 3l) and terminate in spaced relationship with respect thereto. Member 24 is also provided with a pair of longitudinal extending, retaining bosses 32 integral with sides 28 at the uppermost, longitudinal edges of the latter. Bosses 32 as shown, have convex faces, as illustrated in FIG. l, although it will be appre-ciated that bosses 32 could have any suitable 'configuration toperform their intended purpose.

Sealer 14 is best illustrated in FIG. 4 and includes a body 34 of resilient material having a number of longitudinally extending cells defined by a plurality of longitudinally extending webs 36. Body 34 is also provided with a pair of sides 38, a top 40, and a lbottom 42. Sides 38 are provided with a number of substantially parallel grooves 44 therein, each groove defining a slit 46 on the outer face of the respective side 38 to permit uid in the groove 44 to pass out of the latter. The surface segment 48 between each pair of adjacent grooves 44 is slightly outwardly convex as shown in FIG. 4.

Top 40 has a pair of convergent, upper surfaces 50 which extend toward the interior of body 34 as the surfaces 50 approach each other. Since body 34 is of a resilient material, the same may be laterally compressed and, as it is so compressed, surfaces S@ move inwardly of body 34 rather than outwardly thereof by virture of the `dispositions of surfaces 50.

Bottom 42 has an extension 52 provided with a pair of surfaces 54 which terminate at shoulders 56 defined by the upper 4marginal extremities of a pair of convex, outermost s-urfaces 58 at the lower end of extension 52. Sealer 14 is connected to base 12 `by placing extension 52 within member 24 with extension 52 being between gripper elements 30 of member 24 as shown in FIGS. l-3. To ac-complish this, sides 28 may be initially relatively far apart then grouped toward each other when extension 52 is in the proper position therebetween. Elements 30 overlie shoulders 56 to retain extension 52 within member 24 and thereby interconnect base 12 and seal 14.

Cap 16 is formed from a relatively rigid material so as to be substantially self-sustaining when sealer 14 is disposed in a compressed condition between the longitudinally extending sides of cap 16. Sealer 14 is shown in a compressed condition in FIG. l wherein webs 36 are deformed to` permit sides 38 of body 34 to be disposed in relatively close proximity to each other.

Cap 16 is transversely U-shaped whereby to present a top 62 which is integral with and spans the distance between a pair of opposed sides 60, as shown in FIGS. l and 2 of the drawing. Each side 60 is provided, at its normally lowermost free edge, with a longitudinally extending wing 64, each of said wings 64 having an inner surface 66, said surfaces 66 being in opposed relationship and facing toward one another as best shown in FIGS. 1 and 2 of the drawing.

IEach of wings 64 also has an outer surface 68, which surfaces 68 each engage a corresponding retaining boss 32 in complemental mating relationship therewith. Through this engagement, which is in the naturevof a snap-lit, due to the nature of the material from which wings 64 are made, the cap 16 is removably secured to the base 12. To supplement this removably secured relationship between wings 64 and retaining bosses 32, surfaces 54 of sealer 14 engage corresponding inner surfaces 66 of wings 64 whereby, as a -result of sealer 14 being under compression, the wings 64 are urged in an outward direction and thus into their mating relationship with their corresponding retaining bos-ses 32.

When it is desired to remove cap 16, an upward pull is exerted thereupon as by grasping a free portion thereof, whereby to break the retaining relationship between wings `64 and their bosses 32. As the cap 16 is removed from unit 10, the wings `64 pass between bosses 32 and the adjacent surfaces 54 of the sealer 14 which, due to the oompression exerted on the wings 64 during such passage and the nature of the material from which said wings are formed, tend to flatten the wings 64 whereby to facilitate complete removal of the cap 16 from its position surrounding the sealer 14.

As an 4alternative means of providing for the removal of cap 16, each side 60 of cap 16 may be provided with a line of weakness therein, either at the junction of the side with its corresponding wing 64, or at any other suitable location along the line 66, said lines of weakness extending throughout the entire length of each of the sides 60. Thus, upon upward force being applied to cap 16, sides 60 will be severed along such lines of weakness, allowing the major portion of the cap 16 to be removed from the unit, the portion of the sides 60 on the normally lowermost side of the lines of weakness being retained within the joint.

In use, joint insert unit is initially in the assembled condition shown in FIG. 1 with a quantity of an adhesive in each of the grooves 44 of body 34. The adhesive is such that it will not set to any substantial degree within grooves 44 nor will it bond with the inner surfaces of sides 60. However, the adhesive is of a type which, upon contact with the vertical faces of a concrete joint, will bond the outer surface segments of sides 38 to the vertical faces of the joint so that sealer 14 will expand and contract with the adjacent slabs forming the joint.

Unit 10 may be inserted into a mass 70 of soft concrete either by hand or by a vibrating machine, unit 10 being inserted to a depth `such that top 62 is approximately level with the upper surface 72 of mass 70. It is assumed, of course, that unit 10 is of a size and configuration to meet the requisite state constructural specifications. For example, the transverse thickness of sealer 14, i.e., the distance between the outer faces of sides 38, must be between a pair of upper and lower limits; the transverse width, i,e., the distance between the outer surfaces of top 40 and bottom 42 must also be within prescribed limits; and the distance between edge 22 and top `62 also is required to be equal toy a preselected fraction of the total thickness, i.e., the distance between surface 72 and surface 74 of mass 70.

After being inserted in mass 70 the latter sets to a hardened condition and, as it does so, a plane of weakness, denoted as 76 in FIG. 2, is formed by Virtue of the presence of unit 10 in mass 70. This line of weakness may be observed from the side of mass 70. When a break or crack appears along line 76, cap 16 may then be removed from unit 10 by grasping one end of cap 16 and lifting upwardly so as to strip cap 16 from sealer 14.

In the embodiment illustrated, wings 64 will be deformed and their retaining relationship with bosses 32 broken whereby to pass from between bosses 32 and surfaces 54 of bottom 42 and upwardly with sides 60. Bottom 42, by virtue of its resilience, will normally engage the inner surfaces of bosses 32, while elements 30 will maintain the interconnection between base 12 and sealer 14 as cap 16 is stripped from sealer 14. Body 34 will expand only slightly against the faces `80 of mass 70 inasmuch as sides y60 are relatively thin.

As cap 16 in stripped from sealer 14, the adhesive in grooves 44 is squeezed out of the latter through slits 46 and against the adjacent portions of the corresponding faces 80. After a predetermined period of time, the adhesive bonds surface segments 48 to faces 80 to thereby prevent the removal of sealer 14 from the joint defined by faces 80. Thus, as faces 80 move away from each other upon contraction, as shown in FIG. 3, sealer 14 will expand inasmuch as the latter is at all times under compression. When this occurs, sides 38, which are firmly bonded to faces 80, will move uniformly with the latter. Sealer 14 thus effectively prevents any foreign matter from entering the joint and interfering' with the expansion and contraction of mass 70.

Base 12 and cap 16 may be formed from a material capable of being extruded or roll-formed so as to minimize the over-all costs of production thereof. Sealer 14 may be formed from any material capable of being maintained under compression for long periods of time, and yet which will have good qualities of returning to its noncornpressed shape. In this respect, it has been found that neoprene or other similar material is well suited for the purposes of the present invention inasmuch as it is resistant to abrasion and oxidation and is not adversely affected by the presence of oil, gasoline, or other hydrocarbons which are usually found along highways. Such a material is quite flexible and retains it resilience over a wide temperature range without developing a permanent set after full compression thereof. It is also compatible with concrete and with the adhesive that bonds it to the concrete.

Unit 10 may be used in longitudinally extending pavement points las well as transverse joints. When unit 10 is used in both longitudinal and transverse joints, a suitable bonding agent is used to bond seal 14 of the longitudinal unit with seals 14 of the transverse units.

It is noted that the conguration of tip 20 is such as to prevent the removal of sealer 14 from between faces 80 as cap 16 is stripped the-refrom. Sealer 14 is thus maintained in an operative position at all times since tip 20 and the bonding action of the adhesive prevents upward movement of sealer 14 with respect to the joint formed by faces 80.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A joint insert unit to create a concrete joint comprising:

an elongated, .resilient sealer capable of being laterally compressed, said sealer having a pair of opposed side faces each having a longitudinally extending, adhesive receiving groove therein; and

an elongated, relatively rigid cap having a cavity therein, said sealer being disposed within the cavity in a compressed condition, said cap being disposed in covering relationship to the grooves to thereby retain adhesive therein until said cap is removed from the sealer, whereby the sealer with the cap thereon may be inserted to a predetermined depth into a mass of soft concrete and the cap may be removed from the sealer after the concrete in the mass has set to thereby permit said sealer to remain in said mass in said compressed condition.

2. A joint insert unit as set forth in claim 1, wherein said cap is transversely U-shaped and provided with a pair of sides disposed in juxtaposition to and extending along the side faces of said sealer.

3. A joint insert unit as set forth in claim 2, said cap having a wing carried by the free edge of each of said sides, said wings underlying the sealer when the latter is disposed within said cavity.

4. An insert unit as set forth in claim 3, wherein is provided means for retaining the sealer in said mass of concrete when said cap is removed from the sealer.

5. A joint insert unit to create a concrete joint cornprising:

an elongated, resilient sealer capable of being laterally compressed and having a pair of opposed, longitudinally extending side faces, each having a longi- 'tudinally extending adhesive receiving groove there- 1n;

an elongated, relatively rigid cap having a cavity therein, said sealer being disposed within the cavity in a compressed condition with the cap in covering relationship to `the grooves to thereby retain adhesive in the latter until said cap is removed from the sealer; and

a rigid base secured to and extending longitudinally of the sealer and outwardly from the normally lower extremity thereof, said base being provided with a pair of normally vertically spaced ends, there being means `on the upper end of said base for gripping the normally lower extremity of said sealer, said base having a normally lowermost leading edge provided with a longitudinally extending tip to facilitate insertion of the sealer with cap thereon to a predetermined depth in a mass of soft concrete, whereby the cap may be removed from the sealer after the concrete' in said mass has set to thereby permit said sealer to remain in said mass in said compressed condition, said tip having a pair of normally downwardly facing, relatively convergent surfaces defining the normally lowerrnost leading edge for said base.

References Cited UNITED STATES PATENTS ll/l932 5/1936 11/1937 5/1941 6/1964 4/1965 6/1966 10/1966 10/1966 Thompson 94-182 Robertson 94-18 Awbrey 94-17 Kinzer 94-l8.2

`Dohren 94-51 X Crone 94-18 Cooper et al 94-18 Rhodes 94-18 Middlestadt 94-18 JACOB L. NACKENOFF, Primary Examiner. 

1. A JOINT INSERT UNIT TO CREATE A CONCRETE JOINT COMPRISING: AN ELONGATED, RESILIENT SEALER CAPABLE OF BEING LATERALLY COMPRESSED, SAID SEALER HAVING A PAIR OF OPPOSED SIDE FACES EACH HAVING A LONGITUDINALLY EXTENDING, ADHESIVE RECEIVING GROOVE THEREIN; AND AN ELONGATED, RELATIVELY RIGID CAP HAVING A CAVITY THEREIN, SAID SEALER BEING DISPOSED WITHIN THE CAVITY IN A COMPRESSED CONDITION, SAID CAP BEING DISPOSED IN COVERING RELATIONSHIP TO THE GROOVES TO THEREBY RETAIN ADHESIVE THEREIN UNTIL SAID CAP IS REMOVED FROM THE SEALER, WHEREBY THE SEALER WITH THE CAP THEREON MAY BE INSERTED TO A PREDETERMINED DEPTH INTO A MASS OF SOFT CONCRETE AND THE CAP MAY BE REMOVED FROM THE SEALER AFTER THE CONCRETE IN THE MASS HAS SET TO THEREBY PERMIT SAID SEALER TO REMAIN IN SAID MASS IN SAID COMPRESSED CONDITION. 